Mr Condorcet's conjecture concerning the organic perfectibility
of man, and the indefinite prolongation of human life - Fallacy
of the argument, which infers an unlimited progress from a
partial improvement, the limit of which cannot be ascertained,
illustrated in the breeding of animals, and the cultivation of
plants.

THE last question which Mr Condorcet proposes for examination is
the organic perfectibility of man. He observes that if the proofs
which have been already given and which, in their development
will receive greater force in the work itself, are sufficient to
establish the indefinite perfectibility of man upon the
supposition of the same natural faculties and the same
organization which he has at present, what will be the certainty,
what the extent of our hope, if this organization, these natural
faculties themselves, are susceptible of amelioration?

From the improvement of medicine, from the use of more
wholesome food and habitations, from a manner of living which
will improve the strength of the body by exercise without
impairing it by excess, from the destruction of the two great
causes of the degradation of man, misery, and too great riches,
from the gradual removal of transmissible and contagious
disorders by the improvement of physical knowledge, rendered more
efficacious by the progress of reason and of social order, he
infers that though man will not absolutely become immortal, yet
that the duration between his birth and natural death will
increase without ceasing, will have no assignable term, and may
properly be expressed by the word 'indefinite'. He then defines
this word to mean either a constant approach to an unlimited
extent, without ever reaching it, or an increase. In the
immensity of ages to an extent greater than any assignable
quantity.

But surely the application of this term in either of these
senses to the duration of human life is in the highest degree
unphilosophical and totally unwarranted by any appearances in the
laws of nature. Variations from different causes are essentially
distinct from a regular and unretrograde increase. The average
duration of human life will to a certain degree vary from healthy
or unhealthy climates, from wholesome or unwholesome food, from
virtuous or vicious manners, and other causes, but it may be
fairly doubted whether there is really the smallest perceptible
advance in the natural duration of human life since first we have
had any authentic history of man. The prejudices of all ages have
indeed been directly contrary to this supposition, and though I
would not lay much stress upon these prejudices, they will in
some measure tend to prove that there has been no marked advance
in an opposite direction.

It may perhaps be said that the world is yet so young, so
completely in its infancy, that it ought not to be expected that
any difference should appear so soon.

If this be the case, there is at once an end of all human
science. The whole train of reasonings from effects to causes
will be destroyed. We may shut our eyes to the book of nature, as
it will no longer be of any use to read it. The wildest and most
improbable conjectures may be advanced with as much certainty as
the most just and sublime theories, founded on careful and
reiterated experiments. We may return again to the old mode of
philosophising and make facts bend to systems, instead of
establishing systems upon facts. The grand and consistent theory
of Newton will be placed upon the same footing as the wild and
eccentric hypotheses of Descartes. In short, if the laws of
nature are thus fickle and inconstant, if it can be affirmed and
be believed that they will change, when for ages and ages they
have appeared immutable, the human mind will no longer have any
incitements to inquiry, but must remain fixed in inactive torpor,
or amuse itself only in bewildering dreams and extravagant
fancies.

The constancy of the laws of nature and of effects and causes
is the foundation of all human knowledge, though far be it from
me to say that the same power which framed and executes the laws
of nature may not change them all 'in a moment, in the twinkling
of an eye.' Such a change may undoubtedly happen. All that I
mean to say is that it is impossible to infer it from reasoning.
If without any previous observable symptoms or indications of a
change, we can infer that a change will take place, we may as
well make any assertion whatever and think it as unreasonable to
be contradicted in affirming that the moon will come in contact
with the earth tomorrow, as in saying that the sun will rise at
its usual time.

With regard to the duration of human life, there does not
appear to have existed from the earliest ages of the world to the
present moment the smallest permanent symptom or indication of
increasing prolongation. The observable effects of climate,
habit, diet, and other causes, on length of life have furnished
the pretext for asserting its indefinite extension; and the sandy
foundation on which the argument rests is that because the limit
of human life is undefined; because you cannot mark its precise
term, and say so far exactly shall it go and no further; that
therefore its extent may increase for ever, and be properly
termed indefinite or unlimited. But the fallacy and absurdity of
this argument will sufficiently appear from a slight examination
of what Mr Condorcet calls the organic perfectibility, or
degeneration, of the race of plants and animals, which he says
may be regarded as one of the general laws of nature.

I am told that it is a maxim among the improvers of cattle
that you may breed to any degree of nicety you please, and they
found this maxim upon another, which is that some of the
offspring will possess the desirable qualities of the parents in
a greater degree. In the famous Leicestershire breed of sheep,
the object is to procure them with small heads and small legs.
Proceeding upon these breeding maxims, it is evident that we
might go on till the heads and legs were evanescent quantities,
but this is so palpable an absurdity that we may be quite sure
that the premises are not just and that there really is a limit,
though we cannot see it or say exactly where it is. In this case,
the point of the greatest degree of improvement, or the smallest
size of the head and legs, may be said to be undefined, but this
is very different from unlimited, or from indefinite, in Mr
Condorcet's acceptation of the term. Though I may not be able in
the present instance to mark the limit at which further
improvement will stop, I can very easily mention a point at which
it will not arrive. I should not scruple to assert that were the
breeding to continue for ever, the head and legs of these sheep
would never be so small as the head and legs of a rat.

It cannot be true, therefore, that among animals, some of the
offspring will possess the desirable qualities of the parents in
a greater degree, or that animals are indefinitely perfectible.

The progress of a wild plant to a beautiful garden flower is
perhaps more marked and striking than anything that takes place
among animals, yet even here it would be the height of absurdity
to assert that the progress was unlimited or indefinite.

One of the most obvious features of the improvement is the
increase of size. The flower has grown gradually larger by
cultivation. If the progress were really unlimited it might be
increased ad infinitum, but this is so gross an absurdity that we
may be quite sure that among plants as well as among animals
there is a limit to improvement, though we do not exactly know
where it is. It is probable that the gardeners who contend for
flower prizes have often applied stronger dressing without
success. At the same time it would be highly presumptuous in any
man to say that he had seen the finest carnation or anemone that
could ever be made to grow. He might however assert without the
smallest chance of being contradicted by a future fact, that no
carnation or anemone could ever by cultivation be increased to
the size of a large cabbage; and yet there are assignable
quantities much greater than a cabbage. No man can say that he
has seen the largest ear of wheat, or the largest oak that could
ever grow; but he might easily, and with perfect certainty, name
a point of magnitude at which they would not arrive. In all these
cases therefore, a careful distinction should be made, between an
unlimited progress, and a progress where the limit is merely
undefined.

It will be said, perhaps, that the reason why plants and
animals cannot increase indefinitely in size is, that they would
fall by their own weight. I answer, how do we know this but from
experience? -- from experience of the degree of strength with
which these bodies are formed. I know that a carnation, long
before it reached the size of a cabbage, would not be supported
by its stalk, but I only know this from my experience of the
weakness and want of tenacity in the materials of a carnation
stalk. There are many substances in nature of the same size that
would support as large a head as a cabbage.

The reasons of the mortality of plants are at present
perfectly unknown to us. No man can say why such a plant is
annual, another biennial, and another endures for ages. The whole
affair in all these cases, in plants, animals, and in the human
race, is an affair of experience, and I only conclude that man is
mortal because the invariable experience of all ages has proved
the mortality of those materials of which his visible body is
made:

What can we reason, but from what we know?

Sound philosophy will not authorize me to alter this opinion
of the mortality of man on earth, till it can be clearly proved
that the human race has made, and is making, a decided progress
towards an illimitable extent of life. And the chief reason why I
adduced the two particular instances from animals and plants was
to expose and illustrate, if I could, the fallacy of that
argument which infers an unlimited progress, merely because some
partial improvement has taken place, and that the limit of this
improvement cannot be precisely ascertained.

The capacity of improvement in plants and animals, to a
certain degree, no person can possibly doubt. A clear and decided
progress has already been made, and yet, I think, it appears that
it would be highly absurd to say that this progress has no
limits. In human life, though there are great variations from
different causes, it may be doubted whether, since the world
began, any organic improvement whatever in the human frame can be
clearly ascertained. The foundations, therefore, on which the
arguments for the organic perfectibility of man rest, are
unusually weak, and can only be considered as mere conjectures.
It does not, however, by any means seem impossible that by an
attention to breed, a certain degree of improvement, similar to
that among animals, might take place among men. Whether intellect
could be communicated may be a matter of doubt: but size,
strength, beauty, complexion, and perhaps even longevity are in a
degree transmissible. The error does not seem to lie in supposing
a small degree of improvement possible, but in not discriminating
between a small improvement, the limit of which is undefined, and
an improvement really unlimited. As the human race, however,
could not be improved in this way, without condemning all the bad
specimens to celibacy, it is not probable that an attention to
breed should ever become general; indeed, I know of no
well-directed attempts of this kind, except in the ancient family
of the Bickerstaffs, who are said to have been very successful in
whitening the skins and increasing the height of their race by
prudent marriages, particularly by that very judicious cross with
Maud, the milk-maid, by which some capital defects in the
constitutions of the family were corrected.

It will not be necessary, I think, in order more completely
to shew the improbability of any approach in man towards
immortality on earth, to urge the very great additional weight
that an increase in the duration of life would give to the
argument of population.

Many, I doubt not, will think that the attempting gravely to
controvert so absurd a paradox as the immortality of man on
earth, or indeed, even the perfectibility of man and society, is
a waste of time and words, and that such unfounded conjectures
are best answered by neglect. I profess, however, to be of a
different opinion. When paradoxes of this kind are advanced by
ingenious and able men, neglect has no tendency to convince them
of their mistakes. Priding themselves on what they conceive to be
a mark of the reach and size of their own understandings, of the
extent and comprehensiveness of their views, they will look upon
this neglect merely as an indication of poverty, and narrowness,
in the mental exertions of their contemporaries, and only think
that the world is not yet prepared to receive their sublime
truths.

On the contrary, a candid investigation of these subjects,
accompanied with a perfect readiness to adopt any theory
warranted by sound philosophy, may have a tendency to convince
them that in forming improbable and unfounded hypotheses, so far
from enlarging the bounds of human science, they are contracting
it, so far from promoting the improvement of the human mind, they
are obstructing it; they are throwing us back again almost into
the infancy of knowledge and weakening the foundations of that
mode of philosophising, under the auspices of which science has
of late made such rapid advances. The present rage for wide and
unrestrained speculation seems to be a kind of mental
intoxication, arising, perhaps, from the great and unexpected
discoveries which have been made of late years, in various
branches of science. To men elate and giddy with such successes,
every thing appeared to be within the grasp of human powers; and,
under this illusion, they confounded subjects where no real
progress could be proved with those where the progress had been
marked, certain, and acknowledged. Could they be persuaded to
sober themselves with a little severe and chastised thinking,
they would see, that the cause of truth, and of sound philosophy,
cannot but suffer by substituting wild flights and unsupported
assertions for patient investigation, and well authenticated
proofs.

Mr Condorcet's book may be considered not only as a sketch of
the opinions of a celebrated individual, but of many of the
literary men in France at the beginning of the Revolution. As
such, though merely a sketch, it seems worthy of attention.